A formula interpreter is embedded in code_saturne, which can be used through the GUI.In order to call the formula editor of the GUI, click on the button: GUI formula button.
This will call a popup window similar to the following one
 
The formula editor is a window with three tabs:
User expression
This tab is the formula editor. At the opening of the window only the required symbols are displayed. The syntax colorization shows to the user symbols which are required symbols, functions, or user variables. Each expression uses a C-like syntax and must be closed by a semicolon (;). Compared to a true C syntax, the type of local variables does not need to be defined, as they are assumed to de real-valued.
Required symbols must be present in the final user law. A syntax checker is used when the user clicks on the OK button.
Predefined symbols
There are three types of symbols
Useful functions
cos: cosine 
 sin: sine 
 tan: tangent 
 exp: exponential 
 sqrt: square root 
 log: Napierian logarithm 
 acos: arc cosine 
 asin: arc sine 
 atan(x): arc tangent (arc tangent of x in radians; the return value is in the range [-π/2, π/2])
 atan2(y,x): arc tangent (arc tangent of y/x in radians; the return value is in the range [-π, π]) 
 cosh: hyperbolic cosine 
 sinh: hyperbolic sine 
 tanh: hyperbolic tangent 
 abs: absolute value 
 mod: modulo 
 int: floor 
 min: minimum 
 max: maximum 
 Useful constants
pi = 3.14159265358979323846 
 e = 2.718281828459045235
 Operators and statements
+ - * / ^ ! < > <= >= == != && || while if else
Examples
This tab displays examples, which can be copied, pasted, and adapted.